Abstract: Processes for the preparation of esters of N.sub.1 -methyl-10.alpha.-methoxylumilysergol are described, in which lysergol esters are subjected to N-methylation and subsequently to photochemical reaction with methanol/H.sub.2 SO.sub.4. The esters of N.sub.1 -methyl-10-methoxylumilysergol obtained in this way can then be saponified or converted directly into other esters.