. . "The compounds of formula (1A) wherein X is O can be made, for example, by condensing a compound of formula (9) ##STR21## where R1, R2, R3, and R4 are as defined above for formula (1A) and L is a leaving group such as P, Cl, Br, I, NO2, 1,2,4-triazol-1-yl, OSi(CH3)3, arylthio, (C1 -C4) alkylthio, (C1 -C4) alkylsulfonyl, arylsulfonyl, alkoxy, or arylsulfonyl, with an alcohol or phenol of the formula" . .