Asymmetric Sequential Allylic Transfer Reaction for the Synthesis of 2‐(1‐Stannylvinyl)‐1,3‐diols: Concise Synthesis of (−)‐Avenaciolide and (−)‐Isoavenaciolide

Abstract

Stereocontrolled consecutive processes can offer advantages over stepwise transformations by increasing chemical efficacy and saving efforts as a result of a simple operation.[1] During the course of our research program aimed at developing new synthetic methods for the stereoselective construction of pyran rings through stepwise allylic transfer reactions, [2] we disclosed our investigations on transition-metal-catalyzed intramolecular allylations mainly between allene and carbonyl functionalities to afford cyclic compounds with high levels of stereoselectivity.[3] With these observations in hand, we became interested in designing a sequential allylic transfer reaction from 1 with two aldehydes to form acyclic 2-(1-stannylvinyl)-1,3-diols 2, which contain versatile functional groups (Scheme 1).It was envisaged that the sequential allylic transfer reaction starting from 1 could be realized by a three-step sequence as shown in Scheme 1. To provide direct access to 2, we considered the bis(stannyl) compound A as a crucial intermediate. The transformation involves propargylboration Scheme 1. General strategy for the synthesis of 2, and thus natural products 3 and 4, by a sequential approach. L* = chiral ligand.

Progress in the Total Synthesis of Natural Products Embodying Diverse Furofuranone Motifs: A New Millennium Update

“…6.1.2. Yu's synthesis of (À )-avenaciolide ( 9) and (À )-iso-avenaciolide (10) [67] In an elegant stereocontrolled asymmetric cascade, Yu and coworkers synthesized acyclic stannylvinyl 1,3-diols such as 318 and 321 via an allylic transfer/distannation/allylic transfer sequence in one-pot procedure and applied it for a concise total synthesis of avenaciolide (9) and isoavenaciolide (10) (Scheme 35). [67] Thus, addition of nonaldehyde to the allenylstannane 314 in presence of chiral bromoborane S,S-315 resulted in the allenyl carbinol 316 with complete chirality transfer.…”

“…Yu's synthesis of (À )-avenaciolide ( 9) and (À )-iso-avenaciolide (10) [67] In an elegant stereocontrolled asymmetric cascade, Yu and coworkers synthesized acyclic stannylvinyl 1,3-diols such as 318 and 321 via an allylic transfer/distannation/allylic transfer sequence in one-pot procedure and applied it for a concise total synthesis of avenaciolide (9) and isoavenaciolide (10) (Scheme 35). [67] Thus, addition of nonaldehyde to the allenylstannane 314 in presence of chiral bromoborane S,S-315 resulted in the allenyl carbinol 316 with complete chirality transfer. Pd-catalyzed distannation of this intermediate then yielded the allylic tin intermediate 317 which underwent a highly stereocontrolled allyl transfer reaction, again controlled by S,S-315, with methyl glyoxalate to give 318 followed by insitu lactonization to yield the α-hydroxy-γbutyrolactone 319 in 75% yield from 314.…”

Enantioselective Synthesis of a Furan Lignan (+)-Sylvone

“…In our continuous efforts to utilize allenyl functionality, we have demonstrated a highly efficient α-addition of methyl allenoate with aldehydes to furnish the aldol adduct 2 with high levels of enantioselectivity . From a synthetic viewpoint, it was envisaged that aldol adduct 2 would serve as a starting material for a sylvone skeleton (type A ).…”

Intramolecular Carbocyclization of Allenoate-aldehydes with Hexamethylditin Catalyzed by Palladium Complex: Synthesis of Cyclic Dienes

“…3 In this regard, an allene has been proven to be an useful substrate for a variety of transition metal catalytic reactions, particularly for the cyclizations in the construction of carbo-and heterocycles. 4 Recently, we disclosed our discovery of direct cyclization methods for the synthesis of avenacilolide, 5 as a part of the allylic transfer strategy utilizing an allene as substrates or intermediates. 6 To extend this protocol, we reported a cyclization of allenoate-aldehydes 1 mediated by molybdenum carbonyl in the presence of DMSO to direct access naturally occurring canadensolide as shown in Scheme 1.…”