Terpene compounds as drugs. VII. Terpenylhydroxamic acids

Casadio, S; Mantegani, A; Sale, A. O.; Coppi, G

doi:10.1021/jm00295a055

Cited by 3 publications

(1 citation statement)

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“…25 When the reaction temperature is superior to 75°C, Hofmann elimination becomes a competing side reaction. The corresponding known Me esters 34d, [93][94][95][96][97] (80 : 20 (3E/3Z) mixture, were more efficiently obtained using 0.01 mol.-equiv of either Pd(PPh 3 ) 4 , or PdBr 2 /(CH 2 PoPy 2 ) 2 (MeOH/THF, CO, 60 bar, 60°C, 22 h, 52 -55 % yield, respectively, see Supplementary Material). 26 See the Supplementary Material for the corresponding known Me ester 35a.…”

Section: Resultsmentioning

confidence: 99%

A Concise Synthesis ofrac‐Ambrox®viathe Palladium(0)‐Catalyzed Carboalkoxylation of an Allylic Ammonium Salt, as Compared to a Formaldehyde HeteroDiels–AlderApproach

Chapuis

Skuy

Richard

2019

Helvetica Chimica Acta

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Acidic cyclization of either the diethylallylamines 29b or 30, followed by a 1.5 mol‐% Pd‐catalyzed carbomethoxylation of quaternized 31b, leads to the methyl ester 36a. This latter could also be obtained in optically pure form by carbomethoxylation of the corresponding (+)‐acetate. Final reduction‐cyclization may be conducted as earlier described, towards the desired odoriferous rac‐Ambrox® 38a, or its pure (−)‐enantiomer. Generation of a π‐allyl Pd complex from an allylic ammonium salt, followed by carboalkoxylation is novel. In only five chemical steps starting from farnesene 2, the present work constitutes the most concise total synthesis of rac‐Ambrox® 38a to date.

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