Rhodium-Catalyzed Cyclohydrocarbonylation:  Application to the Synthesis of (+)-Prosopinine and (−)-Deoxoprosophylline

Abstract

Efficient convergent total syntheses of (+)-prosopinine (1) and (−)-deoxoprosophylline (4) were accomplished using Rh−BIPHEPHOS complex-catalyzed cyclohydrocarbonylation as the key step. The Rh−BIPHEPHOS complex-catalyzed cyclohydrocarbonylation of I, derived from (R)-serine, at 65 °C and 4 atm of CO and H2 (1:1) in ethanol afforded 6-ethoxypiperidine II, which was transformed to enantiopure (+)-prosopinine (1) in 3 steps. In a similar manner, (−)-deoxoprosophylline was synthesized through cyclohydrocarbonylation of IV derived from (S)-serine, giving 6-ethoxypiperidine V. The key intermediate V was transformed to enantiopure (−)-deoxoprosophylline (4) in 4 steps. These two short total syntheses clearly demonstrate the usefulness of the extremely regioselective cyclohydrocarbonylation process developed in these laboratories for the concise syntheses of piperidine alkaloids and related compounds.

Regulation of mitochondrial ceramide distribution by members of the BCL-2 family

“…Lipid extraction was performed with modifi cations on the Bligh and Dyer procedure ( 25,26 Step 1. Stereoselective addition of vinyl magnesium bromide to ( S )-Garner aldehyde was carried out in tetrahydrofuran (THF), and the crude product was purifi ed by silica gel chromatography based on known procedures ( 31,32 ) …”

Facile Synthesis of Tumor‐Associated Carbohydrate Antigen Ganglioside GM3from Sialic Acid, Lactose, and Serine

“…According to our previous study [8] and related works, [10,11] alcohol 5 was prepared in nine steps with 10 % yield. Protection of the 1-OH in compound 5 by using TBDPS (tert-butyldiphenylsilyl) and cleavage of the Boc group with TFA produced amine 7.…”

Stereoselective Synthesis of β‐Proline Derivatives from Allylamines via Domino Hydroformylation/Wittig Olefination and Aza‐Michael Addition

“…[8] Other groups have developed corresponding syntheses of piperidines. [9,10] The success of this approach was an incentive to try further combinations of the allylic substitution and the hydroformylation reaction. Herein we report syntheses of pyrrolidine derivatives by a domino hydroformylation/Wittig olefination, applied to allylamine derivatives, followed by a separate aza-Michael addition (Scheme 1).…”