This may not be doable from a business/financial standpoint, but I thought I'd mention that a DONE3 business class RTW ticket with travel beginning in Norway currently carries a base price of $5225 which compares favorably to a number of PE fares bought on fairly short notice (which your frequency of trips might imply.) The rules for the Oneworld Explorer require a minimum of 2 stopovers (24h+) enroute, which would be easy if you started and ended the RTW in Oslo - one stopover in Singapore, the other back in Boston. The actual route could be something like OSL-HEL-SIN-NRT-BOS-LHR-OSL or OSL-LHR-BOS-HKG-SIN-HEL-OSL.

Depending on your personal or work needs/requirements, you could also use the ticket for a fair amount of additional travel at no increase in fare. For example, if during your time in Boston you want to use the ticket for travel to, say, California, or pretty much anywhere in North America (which includes Central America and the Caribbean) you could do so. Much depends on your or your employer's desires and policies. Maybe worth considering, anyway.

There are numerous threads on this board describing the Oneworld Explorer and its rules/benefits.