How to generate PWM with duty cycle varying in sinusoidal fashion?
Your circuit won't work because you have a dead short across your supply: -

If you want to approach it this way you need to use a full H-bridge: -

Note that I haven't shown the flyback diodes on the right-side transistors because the bulk diodes in the two MOSFETs serve that purpose.
Of course, if you already have a sinewave signal you could use a PWM modulator such as the LTC6992: -