Some representative monoterpenes have been isomerised under the influence of Schlosser's lithium–potassium mixed superbases, promoting β-elimination reactions. The results are compared with those obtained with butyllithium and LDA. Different selectivities and different reaction yields are achieved as a function of the base employed. These results confirm the particular reactivity of bimetallic reagents
An open and shut case: An interesting bromine‐catalyzed tandem ringopening/cyclization reaction of bicyclic vinylcyclopropanes with chloramine‐T ([TsNCl]Na) has been demonstrated to furnish chiral bicyclic amidine derivatives in good yield. A plausible mechanism has been proposed based on the experimental observations. Ts=p‐toluenesulfonyl.
A new methodology for the synthesis of bicyclo [3.2.0]heptenes from cis-methylvinylcyclopropanes
作者:H.R. Sonawane、B.S. Nanjundiah、M. Udaya Kumar
DOI:10.1016/s0040-4039(00)98522-8
日期:1985.1
A practical photolytic approach has been developed to furnish synthetically useful bicyclo[3.2.O]heptene derivatives from -methylvinylcyclopropanes; such products are not generally accessible by thermal processes owing to the competing retro-ene reaction.
Photoinduced vinylcyclopropane-cyclopentene rearrangement: A methodology for chiral bicyclo[3.2.0]heptenes. Formai syntheses of (±)-grandisol and naturally occurring ()-Δ9(12)-Capnellene and its antipode
作者:Harikisan R. Sonawane、Vishwaniyant G. Naik、Nanjundiah S. Bellur、Virendra G. Shah、Pramod.C. Purohit、M.Uday Kumar、Dilip G. Kulltarni、Jaimala R. Ahuja
DOI:10.1016/s0040-4020(01)91019-1
日期:1991.9
The problem of achieving reaction selectivity in -alkyl vinylcyclopropanes in favour of their rearrangement to cyclopentenes, obviating the competing low energy process of the [1,5] (homo) sigmatropic hydrogen shift, is addressed. It has been demonstrated that the readily available bicyclo[4.1.0]heptenes derived from (+)-Δ3-carene. (1), upon photosensitized irradiation, are conveniently transformed
Total Synthesis of (−)-Vitrenal and Its Biological Activity
作者:Mitsuaki Kodama、Usman S. F. Tambunan、Tetsuto Tsunoda、Shô Itô
DOI:10.1246/bcsj.59.1897
日期:1986.6
(−)-Vitrenal, the enantiomer of the natural sesquiterpene aldehyde isolated from a liverwort, has been synthesized starting from (+)-3-carene, and its activity as a plant-growth regulator has been tested.