Mild and efficient methodology for installation of gem-diallyl functionality on carbohydrate synthons

Abstract

A versatile approach to construct gem-diallyl functionality has been described.

An expedient synthesis of tetrakis(cyclopropylmethyl)methane

“…The crucial reaction, i.e., transformation of 8 to the diallyl compound 9 was achieved by treating it with allyltributylstannane, catalytic AIBN in refluxing benzene in an overall yield of 43%. 5 The 1 H-and 13 C-NMR spectra of the diallyl compound 9 were as expected and only half of the signals were seen. 10b Following the similar protocol of de Meijere and co-workers that has been used in the synthesis of 1, 2 cyclopropanation of the diallyl compound 9 was succesfully achieved by treating 9 with an excess ethereal solution of diazomethane in the presence of catalytic Pd(OAc) 2 , 9 and the tetracyclopropyl derivative 3 was obtained in good yield.…”

“…This communication describes the synthesis of tetrakis(cyclopropylmethyl)methane (3) and its solid state structure. The planned synthesis of 3 consists of an exquisite application of our gem-diallylation approach 5 for the synthesis of the diallyl derivative 9, and subsequent twofold cyclopropanation of 9. The synthesis commenced from the dicyclopropyl acetone (4) which was made according to the known procedure.…”

Synthesis of spirocycles via ring closing metathesis of heterocycles carrying gem-diallyl substituents obtained via ring opening of (halomethyl)cyclopropanes with allyltributyltin

“…1 and catalytic AIBN to give the gem-diallyl derivative 5 in 76% yield (Scheme 2). The structure of 5 was proven, beyond any doubt, by 1 H, 13 C, mass spectroscopy and elemental analysis.…”

Synthesis of Spirocyclic Ethers

“…58 In 2001, Gurjar et al reported the preparation of carbohydrate synthons possessing gem-diallyl functionality. 59 One of these synthons (171) was also closed by RCM to provide spiro compound 172 in 80% yield (Scheme 25). 1 N H C l , T H F 2 5 ° C , 2 h 2 .…”