663619-38-3

Upstream product

• 536-74-3 phenylacetylene 
• 663619-22-5 (3R,4S)-4-((R)-1-Hydroxy-3-phenyl-prop-2-ynyl)-1-(4-methoxy-phenyl)-3-phenoxy-azetidin-2-one 
• 148968-09-6 (+)-(3R,4S)-1-(p-methoxyphenyl)-3-phenoxy-4-oxoazetidine-2-carbaldehyde 
• 663619-31-6 Methanesulfonic acid (R)-1-[(2R,3R)-1-(4-methoxy-phenyl)-4-oxo-3-phenoxy-azetidin-2-yl]-3-phenyl-prop-2-ynyl ester 

Relevant academic research and scientific papers

Synthesis of Optically Pure Highly Functionalized γ-Lactams via 2-Azetidinone-Tethered Iminophosphoranes

A synthesis of optically pure densely functionalized γ-lactams starting from 2-azetidinone-tethered iminophosphoranes has been developed. Full chirality transfer has been accomplished from the enantiomerically pure 2-azetidinones. The addition of lithium acetylides to 4-oxoazetidine-2-carbaldehydes at -78 °C smoothly yielded propargylic alcohols with excellent diastereoselectivities. Propargylic alcohols were converted to mesylates, which by exposure to sodium azide afforded the corresponding azides. Treatment of β-lactams bearing an azido side chain with triphenylphosphine (TPP) gave λ5-phosphazenes (iminophosphoranes, phosphine imines), which were not isolated. The sodium methoxide promoted reaction of the phosphazene β-lactams smoothly provided γ-lactams, through a N1-C2 bond breakage process on the four-membered lactam with concomitant ring expansion, followed by hydrolysis.