Potential Anticancer Agents.¹ I. Model Experiments for Synthesis of 2'-Deoxynucleosides by the 2,3-Episulfide Approach

Thiiranes

“…2-Hydroxy mercaptans are reported to be comparatively stable distillable compounds: cyclization generally is possible via derivatives only. Such derivatives include S-acetyl (93,94,151), O-acetyl (93,94,151), and 0,S-diacetyl derivatives (70,83,93,94,151) of 2-hydroxy mercaptans. By heating these derivatives with aqueous alkali solutions, such as KOH or NaHCOa, they are converted into thiiranes.…”

“…Yields between 25 and 80% are reported for this process; differences between the individual derivatives were not observed. This method was used for making ethylene sulfide (93,151), cyclohexene sulfide (93,151), cyclopentene sulfide (83,94), cholestene sulfide (234,235), dithioglycidol (93,151), hydroxymethyldithioglycidol (70), and dithioglycidyl acetate (151) and its homologs (57). However, there are 1,2diacetates which do not give thiirane upon treatment with alkalies (57).…”

(−)-Sparteine-Mediated Asymmetric Intramolecular Carbolithiation of Alkenes: Synthesis of Enantiopure Cyclopentanes with Three Consecutive Stereogenic Centers

“…82 (1999) 1863 7 ) Such 1,3-cycloeliminations have been observed by us [18], and later by Normant, Marek and co-workers [4], and Nakai and co-workers [12]; for a mechanistic view on this reaction and the assignment of the relative configuration of 9, see [12]. 8 ) Compound rac-11a was prepared in three steps starting from cyclopentene by epoxidation [20], addition of PhCH 2 MgBr [19], and subsequent acetylation.…”

Stereospecifïc total synthesis of (±)-cassipurine, an alkaloid from rhizophoraceae

“…(with an overall yield of 65%) using the method of Goodman et al (5). A stereoselective reaction of 3 with thiolbenzoic acid yields 1P-hydroxy-2a-thiobenzoylpyrrolizidine, 7 , and 2P-hydroxy-lathiobenzoylpyrrolizidine, 7 a , in a 9: 1 ratio.…”