The enantiospecific synthesis of (4S,5R)-and (4S,5S)-4,5-dihydroxydecanoic acid γ-lactones, proposed autoregulators from

Synthesis of Neplanocin A and Its 3′-Epimer via an Intramolecular Baylis–Hillman Reaction

“…13 Interestingly, as noted by the authors, the Z stereoisomer was obtained. This is in contrast with the report by Wightman et al, 14 where the E isomer was reported as the major product. However, closer examination of the data reported by Wightman (J values of 12 Hz for the olefinic protons) suggests that the Z isomer was also obtained in their studies.…”

Structure elucidation and synthesis of (4S,5S,6Z,8E )-5-hydroxydeca-6,8-dien-4-olide [(S,S)-sapinofuranone B]—a novel γ-lactone metabolite of Acremonium strictum

“…The resultant yellow oil was purified by flash chromatography eluting with 40% ethyl acetate in petroleum ether to give alcohol 16 (0.80 g, 80%) as a clear oil; [α] D 25 Ϫ19.5 (c 2.9, CHCl 3 ), [lit. 12 [α] D 23 Ϫ24.1 (c 2.6, CHCl 3 )]; δ H (300 MHz; CDCl 3 ) 1.27 (3H, t, J 7.0, OCH 2 CH 3 ), 1.34 (3H, s, CH 3 ), 1.36 (3H, s, CH 3 ), 1.75-2.05 (3H, m, 3-H 2 and OH), 2.46 (1H, ddd, J 16.5, 8.5 and 7.0, 2-HH), 2.52 (1H, ddd, J 16.5, 9.0 and 6.0, 2-HH), 3.64 (1H, dd, J 11.5 and 4.0, 6-HH), 3.73-3.84 (2H, m, 4-H and 6-HH), 3.92 (1H, td, J 8.0 and 4.0, 5-H), 4.13 (2H, q, J 7.0, OCH 2 CH 3 ); m/z (EI) 217 (M ϩ Ϫ CH 3 , 78%), 201 (9), 183 (20), 171 (18), 143 (61), 131 (40), 111 (100) and 101 (63).…”

Synthesis of the rarely obtained syn-adducts in the reaction of organocopper compounds with 2,3-O-isopropylideneglyceraldehyde. Preparation of optically active epoxy alcohols

“…of all products were consistent with the assigned structures. The specific rotations of (4a), (Sc), (7), and (8) confirmed that the reaction of (1) with the organocopper compounds proceeds without racemization affording syn-adducts (2).…”

“…The antipode of (7) {oil, [&ID +24.8" (c0.7, CHC13)}7 was isolated from strains of Streptomyces griseus,8 and was recently synthesized from 2,3-O-isopropylidene-~-ribose . 7 The epoxy alcohol (5) can also be synthesized from (2) by the sequence tosylation (TsCl, C5HSN), hydrolysis (HC1, H20), and epoxidation (NaOMe, MeOH). For example, the product (5c), which is the intermediate for the synthesis of natural (+)-disparlure, was obtained from (2c) in 78% yield {m.p.…”