Yield:-

Reaction Conditions:

with Schwartz's reagent at 60; for 16 h;Inert atmosphere;

Steps:

14.1 Step 1: (E)-2-(3-Cyclopentylprop-1-en-1-yl)-4,4,5,5-tetramethyl-1,3,2- dioxaborolane

A mixture of HZrCp2Cl (602 mg, 2.34 mmol), prop-2-yn-1-ylcyclopentane (1.23 mL, 8.6 mmol) and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.13 mL, 7.81 mmol) was stirred at 60°C under a nitrogen atmosphere for 16 hours. The residue filtered through silica gel (0 - 20% ethyl acetate in petroleum ether) to afford the title compound (100 mg, 10% purity) as a colorless oil which was used directly in the next step without any further purification.

References:

WO2021/97110,2021,A1 Location in patent:Paragraph 0598; 0599; 0600