The pyrans I (R = Me, H; R1 = H) with BuLi/KOCMe3 or KSiMe3 gave the 2-metalated derivs. I (R1 = K), which reacted with alkyl halides to give I (R = H, Me; R1 = Me, Et, SiMe3, CH2SiMe3); thus the behavior the 4H-pyrans toward organometallic reagents is sim ...
1979