Conformational analysis. 34. Carbon-13 nuclear magnetic resonance spectra of saturated heterocycles. 6. Methylthianes

Molecular mechanics studies (MM4) of sulfides and mercaptans

“…The compounds that have been studied experimentally were examined, and the data were fit well with MM4 in each case. 60 The fit for MM3 was not as Ž . good, although it was fair Fig.…”

“…Several conformational energies are known for methyl-substituted thiacyclohexanes, 60 and it is, of course, desirable that these be well fit. They were determined by NMR measurements in solution, and hence correspond to ⌬G values at various temperatures.…”

First Direct Synthesis of Optically Active 3‐Methylcyclopentene

“…3.4. (-j-(S)-3-Merhylrhiucyclohexane ((-)-(S)-9). As described for the racemate in [32][54], 10.19 g (41.7 inmol) of (-)-8 were cyclized with 15.03 g (62.5 mmol) of Na2S.9H,0 to yield1 1.65 g (34%, see 4.5) (-)-9, a:iy = -7.1 (neat), [a]:iy = -7.6 (neat, d i 5 : 0.9430 [54]), i.e. p = 0.94 (see 4.5).…”

ChemInform Abstract: 13C CHEMICAL SHIFTS ‐ SENSITIVE DETECTORS IN STRUCTURE DETERMINATION. 1. 13C NMR STUDIES OF SATURATED HETEROCYCLES. 4. METHYL‐SUBSTITUTED 1,3‐DIOXANES

“…(1) It has been shown 4 . 1 [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] .2A that 2,4-diaxial Me,Me-interaction in the chair form is usually enough to lead the ring in a 2,5-or 1,4-twist form. ":" (2) However, it has not become fully established whether a 4,6-diaxial Me,Me-interaction is also regularly enough to make the l,4-twist form competitive enough -especially when a residual pseudoaxial interaction exists.…”