Background: Athletes participating in track and field jumping events (long jump, triple jump, high jump, and pole vault) are exposed to ground-reaction forces on the takeoff leg that are several times their body weight. This can cause injuries specific to such activities. Purpose: To determine the incidence of injuries in collegiate jumpers using the guidelines set forth by a 2014 consensus statement on injury surveillance during track and field events. Study Design: Descriptive epidemiology study. Methods: A total of 51 jumpers between April 2016 and March 2017 and 54 jumpers between April 2017 and March 2018 participated in this study. All athletes were from a single college in Japan. Baseline information on athletes participating in the long jump, triple jump, high jump, and pole vault was collected at study enrollment. Practice and competition exposures were reported by the team trainer. Injury incidence was calculated as the number of injuries per 1000 athlete-exposures (AEs). Results: A total of 147 injuries were reported among 16,998 exposures (8.65 injuries per 1000 AEs). The most common injury locations were the posterior thigh and lateral ankle (17.0%), followed by the posterior foot or toe (12.9%); the most frequent type of injury was strain/muscle rupture/tear (21.1%). The most common injury for long jumpers was ankle sprain (23.3%); for high jumpers, flexor hallucis longus tendinosis (15.8%); and for pole vaulters, hamstring strain (13.2%). Conclusion: The overall characteristics are different for each event; therefore, injuries for each event need to be investigated.
2005 Thiopyran derivatives Thiopyran derivatives R 0370 One-Pot Stereoselective Synthesis of Pyrano[3,2-c]benzothiopyrans: A New Generation and [4 + 2] Cycloaddition of ortho-Thioquinonemethides. -An efficient and trans-selective approach to pyranobenzothiopyrans is reported. The key step is a [4 + 2] cycloaddition of ortho-thioquinonemethide intermediates. -(INOUE*, S.; WANG, P.; NAGAO, M.; HOSHINO, Y.; HONDA, K.; Synlett 2005, 3, 469-472; Dep. Environ. Nat. Sci., Grad. Sch. Environ. Inf. Sci., Yokohama Natl. Univ., Yokohama 240, Japan; Eng.) -Jannicke 28-150
O n e -P o t S t e r e o s e l e c t i v e S y n t h e s i s o f P y r a n o [ 3 , 2 -c ] b e n z o t h i o p y r a n s Abstract: Pyrano[3,benzothiopyrans are synthesized from thiosalicylaldehyde derivatives and unsaturated alcohols in the presence of trimethyl orthoformate and a catalytic amount of p-toluenesulfonic acid with complete trans-stereoselectivity via intramolecular [4+2] cycloaddition of ortho-thioquinonemethides. A more efficient generation and cycloaddition of ortho-thioquinonemethides with Lewis acid is also described.In the past decades, a number of studies on pyrans and benzopyrans have been reported while those of their sulfur-containing analogs are rare. 1,2 It is only lately that the studies of benzothiopyrans have attracted attention of a number of research groups. 3 To the best of our knowledge there are relatively few reports touched upon the synthesis of polycyclic pyranobenzothiopyrans. 2b,4 As a result of advances in both synthetic chemistry and biology, there is now an increased demand for an efficient and convenient synthetic method for sulfur-containing polycyclic compounds. 5 On the other hand, intramolecular Diels-Alder reaction is useful in the construction of fused polycyclic compounds, but this reaction finds few application for the sulfur-containing systems.As an extension of our recent studies on the trans stereoselective synthesis of pyrano[3,2-c]benzopyrans from salicylaldehydes and 5-methyl-4-hexen-2-ol, 6 we anticipated that polycyclic pyranobenzothiopyran 4 would be prepared stereoselectively via ortho-thioquinonemethides (3), 2,7 generated in situ from thiosalicylaldehyde derivative 1 and olefinic alcohol 2 (Scheme 1). Here we report a new generation of ortho-thioquinonemethides with acid catalyst and an efficient one-pot trans stereoselective synthesis of pyranobenzothiopyrans.We initially used thiosalicylaldehyde methoxymethyl ether (1b) as the substrate, because thiosalicylaldehyde (1a) was reported to be intractable and extremely susceptible to air-oxidation. 8 The reaction of 1b and 6-methyl-5-hepten-2-ol (2a) was carried out at room temperature in the presence of trimethyl orthoformate (1.2 equiv) and ptoluenesulfonic acid (0.2 equiv) to give tricyclic compound 4a (54%) along with a minor amount of substituted tetrahydropyran 5a (18%, Table 1, entry 1). The structures of 4a 4 and 5a 9 were easily confirmed by their 1 H NMR and 13 C NMR spectra. It is worthwhile to note that 4a had B/C-trans ring junction in high stereoselectivity. The stereoselectivity of this reaction can be explained on the basis of steric repulsion in the exo-transition state of the thiatriene system. 6b Scheme 1In the cases of increased reaction temperature or prolonged reaction time, 4a was obtained as the sole product; no formation of 5a was observed (Table 1, entries 3 and 4). Furthermore, we found that 5a was completely converted into 4a at a temperature above 50°C in the presence of acid catalyst in benzene. These results suggested two possible mechanisms for the formation of 4a from 2a ...
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