Concise and Highly Stereocontrolled Synthesis of 1-Deoxygalactonojirimycin and Its Congeners Using Dioxanylpiperidene, a Promising Chiral Building Block

Abstract

[reaction: see text] A concise and stereoselective synthesis of the chiral building block, dioxanylpiperidene 4 as a precursor for deoxyazasugars, starting from the Garner aldehyde 5 using catalytic ring-closing metathesis (RCM) for the construction of the piperidine ring is described. The asymmetric synthesis of 1-deoxygalactonojirimycin and its congeners 1-3 was carried out via the use of 4 in a highly stereocontrolled mode.

Total Synthesis of (−)‐Balanol, All Stereoisomers, Their N‐Tosyl Analogues, and Fully Protected Ophiocordin: An Easy Route to Hexahydroazepine Cores from Garner Aldehydes

“…[67] Other methods to acquire syn alcohols as the major products by addition of vinyllithium [68] (generated in situ from tetravinyltin and methyllithium) and zinc bromide on Garner aldehyde were not suitable for scaling-up purposes, due to the lower stabilities of the reagents. Diastereomerically pure allylic alcohols 16 a-d were converted into their corresponding MOM ethers 17 a-d by treatment with MOM chloride in quantitative yields.…”

Diastereoselective Synthesis of N‐Boc‐Norpandamarilactonine‐B and Pandamarilactonine‐A

“…The known acetal 6 [9], readily available from L-serine, was treated with p-toluenesulfonic acid in methanol to give the diol which, without further purification, was selectively silylated with tert-butyldimethylsilyl chloride to afford silyl ether 7 in 71% yield from 6. After protection of the secondary hydroxyl group, the resulting methoxymethyl ether 8 was converted to the primary alcohol 9 by deprotection of a silyl group with TBAF (tetrabutylammonium fluoride).…”

Recent Advances in the Total Synthesis of Piperidine Azasugars

“…A synthesis of fagomine 18 and analogs 19 and 20, [63] as well as DGJ (11) and analogs 70 and 144 [64] from d-Garner's aldehyde (derived from d-serine) with a ring-closing metathesis (RCM) as the key step has been reported by Takahata et al, as shown in Schemes 16-19. In the last decade, the RCM reaction [65] has emerged as an extraordinarily powerful and general method for the construction of nitrogen heterocyclic compounds and has relevant application in the field of alkaloid synthesis.…”

“…To demonstrate the efficiency of this approach to azasugars, the same authors described the synthesis of DGJ (11) and its congeners [64] 70 and 144 relying, in the first step, on the addition of a vinyl metal reagent to d-Garner's aldehyde (see Scheme 18 and 19).…”